Glaucoma is an eye disorder in which the optic nerve suffers damage, permanently impacting vision in the affected eye and progressing to complete blindness if untreated. It is often associated with increased pressure of the aqueous humour in the eye. The term ‘ocular hypertension’ is used for cases having constantly raised intra-ocular pressure with or without associated optic nerve damage.
Glaucoma is the second leading cause of blindness worldwide. However, if the condition is detected early enough it is possible to arrest the development or slow down the progression with medical and surgical means.
The major risk factor for most glaucomas and focus of treatment is increased intraocular pressure. Intraocular pressure is a function of production of liquid aqueous humor by the ciliary processes of the eye and its drainage through the trabecular meshwork. Aqueous humor flows from the ciliary processes into the posterior chamber. It then flows through the pupil of the iris into the anterior chamber. From here the trabecular meshwork drains aqueous humor via Schlemm's canal into scleral plexuses and general blood circulation. Glaucoma may be due to reduced flow through the trabecular meshwork (open angle glaucoma) or to complete closure of the iridocorneal angle resulting in the inability of the aqueous fluid to flow from the posterior to the anterior chamber and then out of the trabecular network (angle closure glaucoma).
Medical treatment of glaucoma includes medication and surgery. In particular, intraocular pressure can be lowered with medication, usually eye drops. Both laser surgeries and conventional surgeries are performed to treat glaucoma, which include canaloplasty, laser surgery, trabeculectomy, glaucoma drainage implants.
The development of animal models of glaucoma by intra-ocular hypertonia is still a major issue in experimental research in this disease. The development of reliable models is necessary to understand the physio-pathology of the disease as well as evaluating the therapeutic potential of new molecules.